A majority of the thermostats which are used for controlling heating and/or cooling in a dwelling or a home are mounted on the wall and wires are installed in the wall from the thermostat to remote control apparatus for the heating and cooling apparatus. In a majority of such wall thermostats, a wall plate or subbase is used to mount the thermostat on the wall. Such a wall plate generally has holes for receiving screws so that the plate can be attached to the wall in a level position. The plate has electrical terminals thereon for connecting at least two and possibly more wires from the remote control apparatus. The actual thermostat is then mounted on the wall plate by means of screws received by tapped holes in the wall plate. Certain of the screws either physically hold the thermostat on the wall plate and/or electrically connect the thermostat circuit to the terminals of the wall plate and thus to the remote control apparatus.
When a replacement thermostat is to be installed, whether it be a conventional thermostat or an electric clock thermostat of the type shown in the Carl G. Kronmiller U.S. Pat. No. 2,558,617 issued June 26, 1951, except that the electric clock is either powered by a manually wound spring or a rechargeable battery of the type manufactured by Honeywell Inc. having a type number T8084A DialSet Chronotherm thermostat and T8082A Fuel Saver Chronotherm thermostat, respectively, heretofore, the old thermostat and the wall plate in most cases were removed and the wires are disconnected from the terminals. A new wall plate which matches the replacement thermostat was then mounted on the wall by either screws or adhesive tape and the replacement thermostat was attached to the new wall plate. While the job of replacing a thermostat appears to be rather simple, such a replacement requires that the new wall plate be mounted in an exact level manner, that the wires from the remote control apparatus be connected to the proper terminals of the wall plate and that the replacement thermostat be properly handled and completely connected to the new wall plate. The possibility of an incorrect installation being made is great. Many "do-it-yourself" homeowners, as well as unskilled installers have difficulty in replacing an existing thermostat with a new thermostat when the replacement requires that the subbase of the existing thermostat be removed.
With the greater emphasis on energy conservation, the use of either spring or battery powered clock thermostats for heating and/or cooling systems in homes has increased and there is a sizeable commercial market for such clock thermostats. Obviously, the market will be greater if the replacement cost for such an electric clock thermostat can be kept at a minimum. One way of reducing the cost of the replacement of a thermostat is to make the replacement an easier job by eliminating as much of the difficulty which has heretofore been experienced.
The present invention provides for an adapter wall plate for a replacement thermostat which is mated for many of the wall plates and subbases of thermostats now in use. After the removal of the existing thermostat from its wall plate, the adapter wall plate of the new replacement thermostat is mounted over the existing wall plate and screws in the adapter wall plate are received into the same holes which were used for mounting the original thermostat. As the position of these holes is fixed, as the position of the replacement subbase is then established so that upon the mounting of the replacement thermostat on the adapter wall plate, a proper operation of the heating and/or cooling apparatus can be accomplished without the removal and reconnection of the electrical circuit.